The present invention concerns methods for producing a yarn comprising the steps of: (a) producing a plurality of dope filaments by spinning a polymer solution in sulfuric acid through a multi-hole spinneret, the polymer comprising imidazole groups; (b) coagulating the plurality of dope filaments into an as-spun yarn; (c) contacting the yarn with an aqueous base having a pKa less than or equal to 11; and (d) rinsing the yarn.

According to one embodiment, a fiber sheet includes a plurality of fibers. The plurality of fibers are in a closely-adhered state.

All of the following (1) to (3) are satisfied, where F1 is a tensile strength in a first direction, and F2 is a tensile strength in a second direction orthogonal to the first direction: (1) F2>F1; (2) F1 is 1 MPa or more; and (3) F2/F1 is 2 or more.

According to one embodiment, a fiber sheet includes a plurality of fibers. The plurality of fibers are in a closely-adhered state.

All of the following (1) to (3) are satisfied, where F1 is a tensile strength in a first direction, and F2 is a tensile strength in a second direction orthogonal to the first direction: (1) F2>F1; (2) F1 is 1 MPa or more; and (3) F2/F1 is 2 or more.

Disclosed is a method of manufacturing a nano metal wire, including: putting a metal precursor solution in a core pipe of a needle; putting a polymer solution in a shell pipe of the needle, wherein the shell pipe surrounds the core pipe; applying a voltage to the needle while simultaneously jetting the metal precursor solution and the polymer solution to form a nano line on a collector, wherein the nano line includes a metal precursor wire surrounded by a polymer tube; chemically reducing the metal precursor wire of the nano line to form a nano line of metal wire surrounded by the polymer tube; and washing out the polymer tube by a solvent.

A method for manufacturing an acrylic fiber uses a spinning solution in which an acrylic polymer is dissolved in an organic solvent, the method including reducing an amount of organic solvent by repeatedly spraying water onto coagulated filaments obtained by solidifying the spinning solution and pressing the coagulated filaments with nip rolls. The nip rolls may apply a nip pressure of 0.2 MPa or higher. Thus, a method for manufacturing an acrylic fiber with which an organic solvent in the acrylic fiber can be removed within a short period of time without using a water bath is provided.

The present invention discloses a method for preparing a PET/PTT parallel complex filament with high self-crimpiness, wherein PET and PTT are sliced, dried and crystallized, and then fused separately and subjected to extrusion molding through a parallel-type spinneret plate; oil is applied after cooling; then level 1-3 drafting and heat setting treatment are adopted; and during drafting, a total drafting rate is controlled to be 3 to 3.5, wherein the level-1 drafting rate is 2.8 to 3.0 at a temperature controlled to be 75 to 80° C., according to the method for preparing the PET/PTT parallel complex filament with high self-crimpiness, methods like multi-level drafting for increasing the drafting rate are adopted, and the effects of improving the fiber strength, moderately lowering the breaking elongation, and greatly improving the self-crimpiness are achieved.

The present invention discloses a method for preparing a PET/PTT parallel complex filament with high self-crimpiness, wherein PET and PTT are sliced, dried and crystallized, and then fused separately and subjected to extrusion molding through a parallel-type spinneret plate; oil is applied after cooling; then level 1-3 drafting and heat setting treatment are adopted; and during drafting, a total drafting rate is controlled to be 3 to 3.5, wherein the level-1 drafting rate is 2.8 to 3.0 at a temperature controlled to be 75 to 80° C., according to the method for preparing the PET/PTT parallel complex filament with high self-crimpiness, methods like multi-level drafting for increasing the drafting rate are adopted, and the effects of improving the fiber strength, moderately lowering the breaking elongation, and greatly improving the self-crimpiness are achieved.

This invention relates to a process and a device for manufacturing cellulose-based webs which are directly formed from lyocell spinning solution and in particular for the washing of directly formed cellulose webs.

This invention relates to a process and a device for manufacturing cellulose-based webs which are directly formed from lyocell spinning solution and in particular for the washing of directly formed cellulose webs.

A high-strength hyaluronate fiber, suitable for use in a surgical suture, a lifting thread, a tissue-engineering scaffold, etc., and a manufacturing method thereof are proposed. The method includes (a) controlling a water content of a hyaluronate having a weight average molecular weight of 100-3,000 kDa to 50-95 wt % to prepare a hyaluronate paste, (b) melting the hyaluronate paste having a controlled water content at a temperature ranging from room temperature to 100° C., and then extruding the hyaluronate paste through a nozzle, and (c) drying the extruded spinning fluid to form a fiber. The hyaluronate fiber has the water content of 5-25 wt %, the tensile strength of 3 to 15 kg/mm.sup.2, and a smooth surface with small cracks, so that the hyaluronate fiber can be used for a surgical suture, a lifting thread, a filler for cosmetic surgery, a tissue-engineering scaffold, etc.